From LoveToKnow 1911

PLATFORM (Fr. plateforme, i.e. ground
plan), a word now generally confined to a raised flat structure or
stage, temporary or permanent, erected in a building or in the open
air, from which speeches, addresses, lectures, &c., can be
delivered at a public or other meeting. Similar structures of wood,
brick or stone, are used in railway stations at such a level above the
rails as to enable passengers to have easy access to the carriages;
and in fortification the word is
used of the raised level surface on which guns are mounted. The
earlier uses of the word, such as for a plane geometrical figure,
the ground plan of a building, and figuratively, for a plan,
design, scheme, &c., are now obsolete. In a figurative sense
the term is applied to a common basis on which members of a
political party may agree, and especially in the United
States to the declaration made by a party at a national or
state convention.

As a speaker requires a physical platform from which to deliver his tirade, the term platform refers to the system upon which an application is built and can be used upon. A machine that can play games, such as a Gamecube, a Game Gear, or a Personal Computer, is a game platform.

This is not to be confused with a platform game, which is an entirely different concept altogether.

This article is a stub. You can help by adding to it.

Stubs are articles that writers have begun work on, but are not yet complete enough to be considered finished articles.